Red colored UV curable epoxy system turns clear upon exposure to UV light

Key Features

  • Cationic curing system
  • Not oxygen inhibited
  • Low viscosity
  • Withstands 1,000 hours 85°C/85% RH

Product Description

Master Bond UV15RCL is a red colored, high strength, low viscosity epoxy based UV system for bonding, sealing and coating. The red color serves as an indicator as to whether UV light reaches the UV curable material. If the light reaches the material, the color will change to clear; if not, it will remain red. It is important to note that the change in color does not indicate full cure, but only that the UV light has reached the polymer.

The lamp should emit light with a wavelength range between 320-365 nm, the optimum being 365 nm. The typical energy required is 20-40 milliwatts per cm². Another variable is the distance of the light source from the material that is being cured. Taking into account these factors, full cure can generally be achieved in 30-60 seconds.

UV15RCL is a cationic curing system. It is not oxygen inhibited and will cure in sections up to 1/8 of an inch thick. UV15RCL has lower shrinkage, higher temperature resistance and good chemical resistance.

The system bonds well to a wide variety of substrates including optically clear plastics, acrylics, polycarbonates, metals, composites and many types of rubber. UV15RCL has excellent chemical resistance to water, acids, bases, fuels and many solvents. It features superb physical strength characteristics and withstands rigorous thermal cycling. As is typical with UVs, it has excellent optical clarity and light transmission properties. The service temperature range is -80°F to +350°F. It is 100% reactive and does not contain any solvents or other volatiles.

Cationic systems, such as UV15RCL, tend to have much higher temperature resistance than other UV type systems. Also, adding heat is highly beneficial to enhancing the glass transition temperature (Tg). With a curing schedule of only UV light, the Tg is about 90-95°C. However, when post cured for 1-2 hours at 125°C, the Tg increases to about 125-130°C. Post curing will also increase the product’s chemical resistance. It has wide applicability in the optical, optoelectronic, aerospace, specialty OEM, among many other high-tech industries.

Product Advantages

  • Changes color from red to clear when exposed to UV light (not an indicator of full cure)
  • Very low viscosity, spin coatable
  • Cationic cure, capable of high Tg
  • Exceptionally low shrinkage
  • Good adhesion to many substrates

Industrial Certifications

1,000 Hours at 85°C/85% RH

Meets EU Directive 2015/863




UV15RCL is available is various sizes and units to accommodate customer's needs.

Visual Media

UV15RCL Epoxy Changes from Red to Clear Under UV Light

UV15RCL adhesive is a UV curable, optically clear compound that changes from red to clear once exposed to UV light. This distinctive feature gives users the confidence that penetration of UV light is taking place across the adhesive material, ensuring a thorough and effective curing process.*

Request Information